Samuel hughes



(N0 M d e1.)

S. HUGHES.

GRINDING MILL.

No. 469.145. Patented Feb. 16, 1892.

ms warm cm FNOTO-UTHOY, WASHINQYDN n c UNTTED STATE PATENT OFFICE.

SAMUEL HUGHES, OF CHARLESTON, SOUTH CAROLINA, ASSIGNOR OF ONE-HALF TOXYILLIAM B. CI-IISOLM, OF SAME PLACE.

GRINDING-MILL.

SPECIFICATION forming part of Letters Patent No. 469,145, dated February16, 1892.

Application filed April 9, 1891- Serial No. 388,301. (No model.)

To all whom it may concern:

Be it known that I, SAMUEL HUGHES, a resident of Charleston, in thecounty of Charleston and State of South Carolina, have invented certainnew and useful Improvements in Grinding-Mills; and I do hereby declarethe following-to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to an improvement in grinding-mills adapted moreparticularly for crushing and pulverizing phosphate rock.

The primary object is to provide a machine of such construction that thebulk of the material being operated upon will be thoroughly pulverizedand prepared for use durin'ga single passage through the mill.

A further object is to provide a machine of such construction that thematerial will be immediately removed upon being properly pulverized, andwill not remain in the mill indefinitely, as has been the case in manyinstances heretofore, until it happened by mere luck to Work out or becrowded out.

Still further objects of importance are to provide a machine in whichall the journals are accessible from the outside, where they can be keptproperly lubricated and where they are protected from the grit and dustcoming from the material being milled.

Still another object is to providea machine in which an enormouscentrifugal force can be obtained and one in which a combined rotary andgrinding or rubbing effect is produced upon the material in the mill.

With these ends in view my invention consists in certain novel featuresof construction and combinations of parts, as will be hereinafterdescribed, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a longitudinal sectional viewof my improved mill. Fig. 2 is a front elevation with the end removed.Fig. 3 is a rear elevation with the horizontallyon a suitable block orsupport 1,

where it may be held securely by a bolt or.

band 2 or other convenient means and wooden blocks 3 3, as shown. Thedie.is preferably constructed with a slightly-inwardly-tapering bore 4,and rolls 5 5, preferably cylindrical in form, are arranged toco-operate with this die to crush, grind, and pulverize the material fedinto the mill. To properly balance the machine, I find that three rollsare desirable. These are secured on shafts 6 6, which in turn arearranged equidistant from one another aroundahorizontal drive-shaft 7.The manner of connecting these shafts may be varied; but as the planshown is a practical one I will proceed to describe it as being a partof my present invention. are secured to the main shaft 7 at suitabledistances apart. In the former the shafts are arranged to vibrate orslide radially from the shaft 7, and in the latter they have pivotalconnection. The pivotal connection is effected by passing the end of theshaft through a sleeve 10, wherein it is capable of revolving freely asoccasion requires it, and to prevent endwi'se movement collars orequivalent devices 11 11 are secured on the shafts at the ends of thesleeves. themselves are provided with trunnions 12, by which they aresupported in driver 9. In the large driver sliding journal-boxes 13 13are arranged to slide in and out and the shafts revolve in thesejournal-boxes. Stout spiral springs 15 15, of sufficient tensilestrength to sustain the weight of the rolls and their shafts, areinterposed between the j ournal-boxes and the hub of the driver, theirpurpose being simply to resist the downward tendency of the uppermostroll or rolls when not held out ward by centrifugal force. The drivershold the rolls to their work and prevent twisting or other lateralstrain which would otherwise result. The heads 16 and 17 are secured tothe opposite ends of the circular die, as shown in Fig. 1, and the rockis fed at some convenient point or points through the former.

To regulate the passage of the material through the machine and preventits being fed through too rapidly, feeding-arms 18 18 are secured to themain shaft 7 just inside Apair of drivers 8 and 9- The sleeves the heador casing 16. These arms are pref erably about three in number, and asthey rotate they catch the material and drive it inward. From theenormous speed there is a tendency .to drive the material entirelythrough the die at once before it is ground; but this is prevented bybending the arms a their ends to form hooks 19 19. These catch thematerial and tend to stop it or retard its progress. At the opposite endof the circular die the paddles or fans 20 20 are secured. These devicescreate a draft, which, together with their contact with the pulverizedrock, forces it out through a discharge 21, located at some convenientplace, and, in this manner, the material is removed from the mill, afterwhich it may be screened, and if necessary the coarser material can beagain passed through the mill.

To prevent dust from blowing out of the openings formed for the shafts 66 in the head 17, a disk fan 22 is provided. This is secured to the mainshaft and its Wings 23 2 3 are turned to create an inward draft. Thisfan not only prevents the escape'of air by creating an inward suction,but also prevents the inflow of too much air.

The main shaft may be supported in any suitable bearings, asillustrated, and it is provided with a belt-wheel or other means bywhich it may bedriven- Thus it will be seen from the construction setforth that by the shape given the die and rolls notonly is there arolling and crushing effect produced, but from the fact that theinterior of the die has a conical or tapering form and the rolls acylindrical shape a grinding and rubbing of the material is caused. Inother words, the outer ends of the rolls have to travel farther than theinner ends as the circumference at the outer end of the die is greaterthan it is at its inner end. Hence to compensate for this there must bea slipping as Well as a re.-

tary motion caused by one end trying to catch up with the oth r or oneend waiting for the other, so to speak, and as it seldom happens thatthe rolls bear equally at any time on the die on account of unequalquantities of material getting between them and the die it follows thatthe bearingpoint is continually shifting, and hence the remain ingport-ion of the rolls have to be retarded or accelerated, andconsequently the rubbing and slipping of the rolls alluded to. Thismakes the action doubly effective in pulverizing the rock, and in factrock that would not be as readily crushed by a mere rotary motion ispulverized with ease by this combined rolling and rubbing action.Further, it will be observed that the journals are protected from dust,being all outside of the machine, as dust is prevented from escaping,and by my arrangement of shafts and rolls enormous centrifugal force isattainable.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is.

1. In a grinding-mill, the combination, with a horizontal circulartapering die, means for supporting the die in this position, and ahorizontal drive-shaft extending centrally through the latter, of aseries of rolls having rotary pivotal connection with the drive-shaftand adapted to co-operate in connection with the circular die,substantially as set forth.

2. The combination, with a die and a main drive-shaft, of rolls, shaftsto which the latter are connected, said shafts having rotary pivotalconnection with the drive=shaft, and

driverssecured to the main shaft and having loose sliding connectionwith the roll-shafts, substantially as set forth.

3. Thecombinatiomwithacircular die and heads or shells located at theopposite ends of the die, of a main shaft, rolls connected therewith,and feeding arms connected with the shaft, substantially as set forth.

4, The combination, with a die and main drive-shaft, ,of shafts havingrolls thereon and drivers secured to the shaft outside of the die forsupporting the roll-shafts and the latter having loose slidingconnection with the drivers, substantially as set forth.

5. The combination, with a die and main drive-shaft, of shafts havingrolls thereon adapted to co-operate with the die, drivers secured on themain shaft, sleeves in which the shafts are revolubly supported, saidsleeves having pivotal connection with the driver, journal-boxes havingsliding connection with the otherdriver in which the shafts revolve, andsprings interposed between the hubs of the driver and the journal-boxes.forof air, substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

SAMUEL HUGHES.

I Vitnesses:

W. F. TAYLOR, V. E. Houses.

